How do I remove maple sap from car paintwork?
2nding Goo Gone, worked for me with pine sap on a vehicle. I’m not sure how widely available it is in the UK but this place has it…
I can’t imagine going over an entire car with a rattlecan of WD-40, especially if this is going to be a recurring issue. A friend who does auto detailing recommends washing the car with Dawn Dishwashing soap; apparently it’s high PH will help strip all that stuff off (including any old wax). Do your washing in the shade so the soap can soak a little bit without drying, give it a good scrubbing, rinse, then use a claybar to get any residual stuff off. Claybars can leave some residue so another wash might be necessary, and after all that you might want to consider a coat of wax to make it easier to wash next time.